What do we use energy for?

Various Methods of Electricity Generation

There are various methods of electricity generation dependent on types of energy.
Among resource energies, coal and natural gas are used to generate electricity by combustion (thermal power), Uranium by nuclear fission (nuclear power), to utilize their heat for boiling water and rotating steam turbine.
Among renewable energies, sunlight is directly converted into electricity (photovoltaics), rotation energy by wind is converted into electricity (wind power), rotating water wheel by running water to generate(hydro). Magmatic heat boils underground water to rotate steam turbine to generate (geothermal).
Continuous technology development for them are proceeding to convert resource energies or renewable energies into electricity with less loss. It is also important for the operation of power plant to do maintenance or training of operators.

Thermal Power

Pulverized coal-fired power generation is currently the major method of coal-fired power generation. Coal is pulverized to fine powder and is burned in the boiler. Heat in the boiler boils the water into steam. The steam pressure turns the steam turbine and the generator generates electricity.

A combined cycle power first generates gas by burning fuel in the compressed air.
Pressure of the gas rotates the gas turbine and the generator creates electricity.
Moreover, exhaust heat from gas turbine is utilized for boiling water to generate steam, which rotates turbine to generate.

Integrated coal gasification combined cycle (IGCC) gasifies the fuel coal in the gasifier. Gasified fuel is burnt in the compressed air to generate gas. Pressure of the gas rotates the gas turbine to generate electricity. Furthermore the exhaust gas heat from gas turbine is utilized to boil water into steam to generate electricity.

International comparison of energy efficiencies of thermal power generation

International comparison of thermal power generation efficiency (fossil fuels). Coal fire plants in Japan achieve highest efficiency, generating much electricity with less fuels. Although generation efficiency can be increased by utilizing power generation facilities (or technologies) with newest and highest efficiency, it is important to do maintenance of facility or to keep or increase of operation quality as well.

Nuclear power

Lightwater means normal water, opposite to heavy water. Heat is produced by nuclear fission in the reactor core, then causes the water to boil, producing steam. The steam is used to rotate the turbine to generate electricity, then is cooled in the condenser by sea water and converted back to liquid water. This water is then returned to the reactor core.

Lightwater means normal water, opposite to heavy water. Heat is produced by nuclear fission in the reactor core but heated water is suppressed before boiling by applying a high pressure. This water with high temperature and pressure is sent to the steam generator, boils the water into steam, and then rotates the turbine to generate electricity in the generator, after that it is cooled in the condenser by sea water and converted back to liquid water. This water is then returned to the steam turbine.

Glossary

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